Drawing device



Patented May 2, 1950 l'fTTE D STATES PATENT 0 F F 1 CE 2,506,426 .DRAWING DEVICE" Sorenfli. B. Larsen, Colii'nsville;v Ill. A'npli'cation' numb-er 2e, HMQj-Seri'a'ILNo. 718,314. 210mm. (areas-a e) Thepresentinvention relates" generally to 'di'aftingiinstrum'ents; and more particularly to adraft'ing instrument for making parallel lines and for obtaining measurements therebetween and therealong on abl'ackboard;

There has long existed the need of an instru ment-Tor facilitating the making of parallel lines ona; blackboard. The use of the. well-known Tsquare to make horizontalparallel lines is-exzceedi'ngly difficult since itis required to hold the Tsquare with: one hand while drawing; a line with chalk? held in. the other hand. It iseven more diflicultto: draw vertical: parallel lines by the: use-of a 1:" square and triangle; or the like; guided along." the top edge-0f the T squaresince onehand: must now hold and? direct both. the

1: square and. theitriangle'.

' Therefore, it is an obj eat-of the": present inven- "ti'on to provide a. novel drafting instrument: by which. parallel lines may be readily madeon; a blaclebo'ardor'thelike.

Another object is to provide a novel drafting instrumentby means: of which parallel lines may herea'dily spaced fractional OTWhoIe'unitS-apaTt.

Anothenobjectisrtoprovide!anovelsupport and' gnide'for' adapting a. T square to blackboard--use :in' the making of parallel lines.

Another object is to provide anovel: drafting instrumentior use on' a blackboard; or! the like, by which: parallel: lines, vertically in respect to distances therebetween, andiwhich servesas a. support and guide for a triangle in making vertical parallel lines and in spacing the same asd'esire'zl Another object is to provide a novel. drafting device which facilitates the making of. parallel lines on a blackboard-,or the-like.-

Another object is to provide a novel drafting device for making parallel lines on a blackboard,

'or thelike; which is readily-applied to andremoved from thesurf-ace of a blackboard, or the "like; without mar-ringor in any wise injuring the surface thereof.

Qther objects are to provide a novel drafting deviceforusaonblack-board's; and the like, which is sturdy-in construction, which is inexpensive to make; which is readily fabricated, andwhich is simple in design and form, facilitating maximum, eflicient employment of the same by a user after minimum instruction.

The foregoing and othen-objects and advantages are apparent from the following description taken with the aocompanyinggdrawing, in which:

Fig. 1 is a plan view of a drafting device con+ s'tructed in accordance with the teachings of the may" be: readily spaced including a base-portion 38' and'returned All which extend around the stem 36.

"inches; providing ascale 2 present" invention, a portion'there'of heing brol'ien away" to illustrate details;

Fig. '2 is an enlarged cross-sectional"view the line" 2- -2' of Fig; 1, a supporting black-boa?! surface being indicated in dotted lines p 3' is an eni'a'rg'ecl cross s'ectional view-tn the li'ne 3--3- oi'Fig'. 1

Fig. 4' is an enlarged cross-s'et-xtional view the line 3-kl of Fig. 1, sh'owing 'a med'ifiect con struction;

Fig. 5 i's across-sectional view on the:l-ine i'-l ol'Fi-g. 2

Fig. 6 is an enlarged cro'ss-sectional 'view"on theline- 6- 6' of Fig. and

Fig. 7 is a view showing the drafting: device applied to a bl'ackb'oard, several selected positions 101- the movable memberbeing shown in dotted -l-I-16;-

Referring to the-drawing more. particularlyby reference numerals, 150' indicates generally :a

in accordance with the: The drafting guid'ei member drafting: device formed-i teachings of the: present invention. device It includes a support: and

12, a; movable member 1Y4 supporting. a: sheath if; and an index member '20 between. the: legs;- 22- and 24 by: a threaded shaft '28 secured to the suction cup 26 which extends through an opening in the night 26 and -is- -eri ga'gcd by aninternally thr 'ea'ded cap 30. The

cutersurface or the bi'ght" 20 is shown astmarlied ofi in inches, providing a scaleil'for' measuring. purposes;

The movable membei' l 4is formed as a 1' square including" a head 34 anda stem 36' which may comprise two pieces secured thgether by a suitable means, or which may be of integral construction.

The stem 36" slidingl'y receives the= sheath f6; which: is of the cross section shown in Figit flanges I The base portion 38'- is" marked on on its outer 'surifac' in poses. Inwardly directed bosses 42 arfbi'lfifi in the base portion 38 to frictionally engage the stem 36 to assist in maintaining the sheath l6 at any particularadjusted position. A manipulating knob 44 isisfecured to the sheath lfi'intermediate the ends-thereof. The sheath l6 and the stem 36 include apertures 46 and 48, re-

n f'or measurin pun J1 for hanging the sheath l6 and mov- M on a nail, or the like, when not spectively, able member in use.

The index member to the form clearly shown in Figs. 2 and 5, and includes a finger portion 50 and a mounting porl8 comprises a wire looped tion 52. The mounting portion 52 engages a groove 54 in the top of a knob 56 secured to the stem 36 adjacent the support and guide member I! by a screw 58, or the like. Manifestly, the index member 18 may take other forms. The finger portion 50 of the index member 18 extends over the scale 32 marked on the member [2.

A stem 36 of modified cross section is shown in Fig. 4. The stem 36 has opposed marginal grooves 31 which receive returned flanges 40' of the sheath flush with the undersurface of the stem 36. This construction eliminates contact of the returned flanges with the supporting blackboard.

In use, the drafting device In is mounted on a blackboard 60 through the medium of the suction cups 26, as is shown in Figs. 2 and 7. Usually the member 12 will be disposed vertically although it is manifest that the member I2 may be disposed at any angle desired. After the device I0 is mounted in a selected position, the suction cups 26 permit sliding thereof, particularly on a smooth blackboard, obviating removal of the device In in changing the angle thereof. The movable member 14 slides in respect to the supporting member H, the T head 34 being trapped in the channel of the member l2 and'slidable longitudinally thereof. It is to be understood that the head 34 may form an L with the stem 36, a construction adapted to increase the limit of the scale, for a given length of the member l2. It is clear that the user of the device l0 need but steady the movable member is while making parallel lines, since the support and guide [2 prohibit the pivotal movement thereof during the drawing of lines on the blackboard 60. The sheath l6 forms an extension for the stem 36, in effect, and provides a scale which may be used whena triangle or other instrument is being used to draw lines.

-'Ihe'bosses 42 assist in maintaining the sheath IS in a selected position. The knob 44 facilitates sliding manipulation of the sheath l6 and serves for holding the movable member l4 and the sheath l6 while drawing horizontal parallel lines. The index member l8 facilitates movement of the member l4 along the member [2 distances of even units employed in the scale 32. For example; should the upper edge of the member I4 be at some figure as four and seven-sixteenths inches, to move the member l4 three whole units, it is but necessary to place the finger portion 50 of the index member IS on the most convenient whole unit and then move the member l4 three units with the finger portion 50 as the guide, which will readily and speedily bring the member Hi to a position with the upper edge thereof adjacent the seven and seven-sixteenths inches index line. -,;.;It is apparent that the support and guide [2 may be employed to support and guide a standard .1 square, and it is to be understood that this novel feature is an important part of the present invention. Y

It is apparent that there has been provided a drafting device which fulfills all the objects and advantages sought therefor.

It is to be understood that the foregoing description and the accompanying drawings have been given by way of illustration and example. It is also to be understood that changes in form of the several parts, substitution of equivalent elements and rearrangement of parts, which will be readily apparent to one skilled in the art, are contemplated as within the scope of the present invention, which is limited only by the claims which follow.

What is claimed is:

1. In combination, a drafting device comprising an elongated support and guide member of substantially channel cross section including spaced flanges, spaced suction cups connected to said support and guide member on the flanged side for mounting the same on a supporting surface with the spaced flanges directed towards such supporting surface for substantially instantaneous removal therefrom, and a headed mem: ber including a stem and head disposed with the head slidably trapped within the channel of said support and guide member and the stem extending at an angle thereto when said drafting device is operatively mounted upon a supporting surface, so that said drafting device is adapted for ready use upon a blackboard or other vertical surface.

2. In combination, a drafting device comprising an elongated support and guide member of substantially channel cross section having graduations on the upper surface, spaced suction cups connected to said support and guide member on the flanged side for mounting the same on a supporting surface with the spaced flanges directed towards such supporting surface for substantially instantaneous removal therefrom, a headed member including a stem and head disposed with the head slidably trapped within the channel of said support and guide member and the stem extending at an angle thereto when said drafting device is operatively mounted upon a supporting surface, so that said drafting device is adapted for ready use upon a blackboard or other vertical surface, and an adjustable pointer mounted on the stem of said headed member including a portion cooperatively disposed in relation to said gradua tions on said support and guide memben' SOREN K. B. LARSEN.

REFERENCES CITED v The following references are of record in the file ofthis patent: I r UNITED STATES PATENTS McDonnell -Q. Mar. 6, 1945 

